EP3003001B1

EP3003001B1 - Cooling system for use with a power electronics assembly and method of manufacturing thereof

Info

Publication number: EP3003001B1
Application number: EP15186925.2A
Authority: EP
Inventors: Charles E. Kusuda
Original assignee: Boeing Co
Current assignee: Boeing Co
Priority date: 2014-09-30
Filing date: 2015-09-25
Publication date: 2020-11-04
Anticipated expiration: 2035-09-25
Also published as: CA2898306A1; CN105472943A; BR102015021691A2; EP3003001A2; CA2898306C; US20160095248A1; CN105472943B; US10576589B2; BR102015021691B1; EP3003001A3

Description

BACKGROUND

The field of the present disclosure relates generally to power electronics assemblies and, more specifically, to cooling systems for power electronics assemblies.
At least some known electronics systems, such as those included in avionics platforms, include an interface that supports a plurality of electronic components such as line-replaceable units (LRUs). A LRU is generally defined as a modular component capable of being quickly and easily interchangeable at the interface with a replacement component. During operation, LRUs generate heat that must be dissipated to ensure the LRUs continue to function properly for extended durations. At least some known cooling systems utilize cooling liquid to dissipate heat from the LRUs. For example, in a two-phase cooling system, cooling liquid is discharged towards the LRUs and the cooling fluid's latent heat of vaporization is used to cool the LRUs. In such systems, each LRU generally has its own dedicated cooling fluid supply assembly whose equipment size and cooling capability is selected based on a heat load generated by each associated LRU. As such, having each cooling fluid supply assembly tailored to each LRU increases equipment requirements, and thus increases the weight of an overall assembly, such as the avionics platform.
Prior art document WO 97/43887 A discloses an atomizer for atomizing a liquid coolant which is positioned inside a sealed housing. A plurality of atomizers, which appear to be identical, are located in a spray plate in a customized pattern such that rows of the atomizers are located between rows of heat generating components arranged in the sealed housing. The atomized liquid coolant is distributed as a thin film over the surface of the heat generating components and the wall of the sealed housing. Heat is transferred from the surface of the heat generating components by vaporization of at least a portion of the thin film liquid coolant. The coolant vapor condenses on the housing and other cool surfaces and returns to the liquid state. The system heat is then removed from the outer surfaces of the housing using conventional heat transfer mechanisms.
Document US 2006/118292 A1 discloses a heat exchange apparatus which includes at least one heat exchanger, an intake manifold, and at least one multichip module. Where the intake manifold is in fluid communication with each heat exchanger and where the intake manifold is capable of providing the heat exchange medium separately to each heat exchanger. Where the each multichip module is positioned at least adjacent to at least one heat exchanger, such that heat can transfer between each multichip module and at least one heat exchanger.
And document US 2007/209782 A1 discloses a cooling system for heat-generating structures which comprises a plurality of heat exchangers, a structure which directs flow of the fluid coolant substantially in the form of a liquid to each of the plurality of heat exchangers, and a structure which reduces a pressure of the fluid coolant to a pressure at which the fluid coolant has a boiling temperature less than a temperature of the heat-generating structures. Each of the plurality of heat exchangers is in thermal communication with at least one of the heat-generating structures and has an inlet and an outlet. Thermal energy from the heat-generating structure causes the fluid coolant substantially in the form of a liquid to boil and vaporize in each of the plurality of heat exchangers so that the fluid coolant absorbs thermal energy from the heat-generating structure as the fluid coolant changes state.

BRIEF DESCRIPTION

In one aspect, a cooling system for use with a power electronics assembly is provided which has the features of claim 1. Preferred embodiments of this cooling system form the subject matter of dependent claims 2-5.
Further a power electronics assembly comprising such a cooling system is provided as defined in claim 6.
In another aspect, a method of manufacturing a cooling system for use with a power electronics assembly is provided which has the features of claim 8. A preferred way of carrying out the method is defined in dependent claim 9.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram of an exemplary aircraft production and service method.
FIG. 2 is a block diagram of an exemplary aircraft.
FIG. 3 is a schematic illustration of an exemplary power electronics assembly.
FIG. 4 is a perspective schematic illustration of an exemplary manifold that may be used with the cooling system shown in FIG. 3 taken along Line 4-4.

DETAILED DESCRIPTION

The implementations described herein relate to cooling systems for use in dissipating heat from an array of electronic components, such as line-replaceable units (LRUs). Specifically, the implementations described herein include a centralized cooling system for the array of LRUs such that each LRU will not have its own self-contained cooling system. The cooling system includes a first manifold that enables cooling fluid to be discharged towards each LRU in the array substantially simultaneously, and a second manifold that collects the cooling fluid discharged towards each LRU. In one implementation, the cooling system is a closed-loop two-phase cooling system such that vaporized cooling fluid collected in the second manifold is channeled towards a single condenser. The condenser condenses the vaporized cooling fluid and replenishes the cooling fluid in the first manifold with the condensed cooling fluid.
Returning the heat laden vapor/liquid mixture to the condenser, wherein the heat is dissipated to a secondary fluid stream, enables lower ambient temperatures surrounding the centralized LRU installations to be utilized. This is beneficial when the cooling system is implemented in a vehicle. A second benefit of the centralized 2-phase system is reduced power consumption by pumps in the system when compared to pump and fan power requirements for single phase and air-based cooling systems. Moreover, the centralized 2-phase cooling system has higher reliability caused by robust redundant system components and reduced LRU complexity. As such, centralizing the cooling system for the array reduces cooling equipment requirements by not having to individually size equipment in self-contained cooling systems, thereby reducing the weight of an overall assembly.
Referring to the drawings, implementations of the disclosure may be described in the context of an aircraft manufacturing and service method 100 (shown in FIG. 1) and via an aircraft 102 (shown in FIG. 2). During pre-production, including specification and design 104 data of aircraft 102 may be used during the manufacturing process and other materials associated with the airframe may be procured 106. During production, component and subassembly manufacturing 108 and system integration 110 of aircraft 102 occurs, prior to aircraft 102 entering its certification and delivery process 112. Upon successful satisfaction and completion of airframe certification, aircraft 102 may be placed in service 114. While in service by a customer, aircraft 102 is scheduled for periodic, routine, and scheduled maintenance and service 116, including any modification, reconfiguration, and/or refurbishment, for example. In alternative implementations, manufacturing and service method 100 may be implemented via platforms other than an aircraft.
Each portion and process associated with aircraft manufacturing and/or service 100 may be performed or completed by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include without limitation any number of aircraft manufacturers and major-system subcontractors; a third party may include without limitation any number of venders, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.
As shown in FIG. 2, aircraft 102 produced via method 100 may include an airframe 118 having a plurality of systems 120 and an interior 122. Examples of high-level systems 120 include one or more of a propulsion system 124, an electrical system 126, a hydraulic system 128, and/or an environmental system 130. Any number of other systems may be included.
Apparatus and methods embodied herein may be employed during any one or more of the stages of method 100. For example, components or subassemblies corresponding to component and subassembly production process 108 may be fabricated or manufactured in a manner similar to components or subassemblies produced while aircraft 102 is in service 114. Also, one or more apparatus implementations, method implementations, or a combination thereof may be utilized during the production stages 108 and 110, for example, by substantially expediting assembly of, and/or reducing the cost of assembly of aircraft 102. Similarly, one or more of apparatus implementations, method implementations, or a combination thereof may be utilized while aircraft 102 is being serviced or maintained, for example, during scheduled maintenance and service 116.
As used herein, the term "aircraft" may include, but is not limited to only including, airplanes, unmanned aerial vehicles (UAVs), gliders, helicopters, and/or any other object that travels through airspace. Further, in an alternative implementation, the aircraft manufacturing and service method described herein may be used in any manufacturing and/or service operation.
FIG. 3 is a schematic illustration of an exemplary power electronics assembly 200. In the exemplary implementation, power electronics assembly 200 includes an array 202 of line-replaceable units (LRUs) 204 and a cooling system 206 is coupled to array 202. Each LRU 204 generates heat when in operation, and cooling system 206 facilitates dissipating heat from array 202. Cooling system 206 includes a fluid supply 208, a first manifold 210 coupled in flow communication with fluid supply 208, and a second manifold 212 coupled in flow communication with fluid supply 208. First and second manifolds 210 and 212 are also coupled in flow communication with array 202 of LRUs 204. Specifically, first manifold 210 is coupled upstream from array 202, and second manifold 212 is coupled downstream from array 202. Moreover, fluid supply 208 includes a fluid reservoir 214 that stores an amount 216 of cooling fluid therein, and a first pump 218 at least partially submerged in amount 216 of cooling fluid.
The cooling fluid may be any cooling fluid that enables power electronics assembly 200 to function as described herein. For example, in one implementation, the cooling fluid has a temperature tolerance of greater than about 250 °C, such as hydrofluoroether-based cooling fluids. Moreover, in an alternative implementation, cooling system 206 includes a filter coupled upstream from array 202. For example, the filter may be coupled between a condenser 220 and first manifold 210. The filter may be either a physical filter or a chemical filter that facilitates removing impurities from the cooling fluid before being discharged towards array 202.
In operation, fluid supply 208 channels cooling fluid towards first manifold 210 thereby discharging the cooling fluid towards each LRU 204 in array 202 substantially simultaneously. Specifically, first pump 218 discharges amount 216 of cooling fluid towards first manifold 210, first manifold 210 discharges the cooling fluid towards array 202, and second manifold 212 collects the cooling fluid discharged towards each LRU 204 in array 202. In some implementations, first manifold 210 includes a plurality of flow control orifices (not shown in FIG. 3), and discharges the cooling fluid at a flow rate and a pressure that atomizes the cooling fluid discharged towards each LRU 204. At least a portion of the cooling fluid vaporizes when contacting LRUs 204, and the latent heat of vaporization of the cooling fluid facilitates extracting heat from LRUs 204. As such, second manifold 212 collects a flow of vaporized cooling fluid and a flow of residual cooling fluid remaining in liquid form. The flow of residual liquid cooling fluid is separated from the vaporized cooling fluid, recycled towards fluid supply 208, and added to amount 216 of cooling fluid. The flow of vaporized cooling fluid and, in some implementations, a portion of residual cooling fluid is channeled towards condenser 220 via a return line 222 via a negative pressure in the closed loop system.
Condenser 220 may be any heat exchanger type device that enables cooling system to function as described herein. In the exemplary implementation, condenser 220 includes a heat exchanger 224 and a condenser reservoir 226 coupled to heat exchanger 224. Heat exchanger 224 includes a housing 228, a heat exchange conduit 230 extending through housing 228, and a fan 232 coupled in flow communication with housing 228. Condenser reservoir 226 includes an amount 234 of condensed cooling fluid, and a second pump 236 at least partially submerged in amount 234.
In operation, condenser 220 receives the flow of vaporized cooling fluid from second manifold 212 via return line 222. Return line 222 is coupled in flow communication with heat exchange conduit 230 such that the flow of vaporized cooling fluid is channeled therethrough. Moreover, return line 222 is sized to reduce sonic velocities, is compatible with condensed vapors, and includes insulation to reduce excess vapor condensation. Fan 232 operates such that a flow 238 of cooling airflow is drawn through housing 228, which cools the flow of vaporized cooling fluid. The flow of vaporized cooling fluid condenses and facilitates forming amount 234 of condensed cooling fluid. Second pump 236 then discharges amount 234 of condensed cooling fluid towards fluid supply 208 via a supply line 240. As such, in some implementations, condenser 220 operates to substantially continuously replenish amount 216 of cooling fluid in fluid reservoir 214.
In an alternative implementation, first and second manifolds 210 and 212, array 202, and fluid supply 208 define an equipment rack 242. In such an implementation, multiple equipment racks 242 may be coupled in parallel with a single condenser 220. As such, the flow of vaporized cooling fluid and the portion of residual cooling fluid from each second manifold 212 of the multiple equipment racks 242 are channeled towards the single condenser 220. Condenser 220 can then selectively replenish the cooling fluid in each fluid reservoir 214 of the multiple equipment racks 242 via a series of valves coupled along supply lines 240.
FIG. 4 is a perspective schematic illustration of first manifold 210 taken along Line 4-4 (shown in FIG. 3). In the exemplary implementation, a plurality of flow control orifices 244 are defined in first manifold 210. Flow control orifices 244 facilitate coupling first manifold 210 in flow communication with array 202 of LRUs 204 (each shown in FIG. 3) such that cooling fluid can be discharged from first manifold 210 towards LRUs 204. For example, at least one flow control orifice 244 is substantially aligned with each LRU 204. Moreover, each flow control orifice 244 substantially aligned with respective LRUs 204 is sized based on a heat load generated by each LRU 204. Specifically, flow control orifices 244 are sized such that a flow rate of cooling fluid discharged therefrom is selected based on a heat load generated by LRUs 204 substantially aligned with each flow control orifice 244.
For example, greater sized flow control orifices 244 are substantially aligned with LRUs 204 that generate more heat, and smaller sized flow control orifices 244 are substantially aligned with LRUs 204 that generate less heat. Moreover, for example, for an exemplary LRU 204 requiring a heat dissipation load of 3.5 kiloWatts (199.22 BTU/minute), the calculation of the required water coolant flow rate (given heat of vaporization of water of 2260 kiloJoules/kilogram) would be 0.0000929 cubic meters/minute (0.0246 gallons/minute), from which a required exemplary orifice size of 1.32 centimeters (0.52 inches) may be calculated, for a first manifold pressure of 2.82 kilograms/square centimeter (40 pounds/square inch) and a pressure drop of 2.985 kilopascals (0.433 pounds/square inch). As such, cooling fluid is discharged from first manifold 210 at different flow rates even when a flow rate of cooling fluid channeled towards first manifold 210 from fluid supply 208 (shown in FIG. 3) is substantially constant.
Cooling system 206 also includes a self-sealing connector 246 coupled between first and second manifolds 210 and 212, and each LRU 204 in array 202 such that each LRU 204 is selectively uncouplable from first and second manifolds 210 and 212. The connections between each LRU 204 and first and second manifolds 210 and 212 are designed to reduce leakage, while enabling LRU removal and replacement without losses in system pressure. This function should be completed while ensuring excess pressure penalty to pump 218 is avoided, and ensuring exhaust of hot vapor/liquid flow from LRUs 204 is not obstructed.
Referring to FIG. 4, each self-sealing connector 246 includes a receptor portion 248 coupled to first manifold 210, and an insertion portion 250 coupled on opposing sides of each LRU 204. When LRU 204 is coupled between first and second manifolds 210 and 212, insertion portion 250 is received within receptor portion 248 and cooling fluid discharge from first manifold 210 is enabled. When LRU 204 is uncoupled from first and second manifolds 210 and 212, insertion portion 250 is uncoupled from receptor portion 248 and receptor portion 248 self-seals via a valve (not shown), for example, such that cooling fluid discharge from first manifold 210 is disabled. As such, LRUs 204 are quickly and easily removable from array 202, and interchangeable with a replacement LRU.
The systems and methods described herein relate to power electronics assemblies and systems for dissipating heat therefrom. Specifically, the power electronics assembly includes an array of line-replaceable units (LRUs) that generate heat during operation thereof. The cooling system for the array is a centralized assembly such that each LRU does not have its own self-contained cooling system. More specifically, the cooling system described herein includes a first manifold that enables cooling fluid to be discharged towards each LRU in the array substantially simultaneously, a second manifold that collects the cooling fluid discharged towards each LRU, and a single pump that channels cooling fluid towards the first manifold. An amount of cooling fluid discharged towards each LRU is selected as a function of a size of flow control orifices defines in the first manifold. As such, the systems and methods described herein provide a centralized cooling system that facilitates simplifying an arrangement of the cooling equipment, and that facilitates reducing the weight of an overall system incorporating the centralized cooling system.
This written description uses examples to disclose various implementations, including the best mode, and also to enable any person skilled in the art to practice the various implementations, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

A cooling system (206) for use in a vehicle with a power electronics assembly (200) comprising an array (202) of line-replaceable units (204), said cooling system comprising:
a first manifold (210) coupled in flow communication with the array (202) of line-replaceable units (204); and

a fluid supply (208) coupled in flow communication with said first manifold (210), said fluid supply (208) configured to channel cooling fluid towards said first manifold (210) such that the cooling fluid is discharged towards the line-replaceable units (204) in the array (202) substantially simultaneously; characterized by further comprising:
a second manifold (212) coupled in flow communication with the array (202) of line-replaceable units (204), wherein said second manifold (212) is configured to collect the cooling fluid discharged towards the line-replaceable units (204), the collected cooling fluid comprising a flow of vaporized cooling liquid and a flow of residual cooling fluid remaining in liquid form, the second manifold (212) being configured to recycle the flow of residual liquid towards the fluid supply (208); and

a condenser (220) coupled in flow communication with said second manifold (212) via a return line (222) which is configured to receive the flow of vaporized cooling fluid and channel it towards the condenser (220), wherein said condenser (220) is configured to:
receive the flow of vaporized cooling fluid from said second manifold (212) through said return line (222),

condense the vaporized cooling fluid and form condensed cooling fluid, and

recycle the condensed cooling fluid towards the fluid supply (208).
The system (206) in accordance with Claim 1, wherein said first manifold (210) is configured to discharge the cooling fluid at a flow rate and a pressure that substantially atomizes the cooling fluid discharged towards the line-replaceable units (204).
The system (206) in accordance with Claim 1 or 2 further comprising a plurality of flow control orifices (244) in said first manifold (210), wherein at least one of said plurality of flow control orifices (244) substantially aligns with each line-replaceable unit (204) in the array (202).
The system (206) in accordance with Claim 3, wherein said plurality of flow control orifices (244) are sized at least in part based on a heat load generated by the line-replaceable units (204).
The system (206) in accordance with any one of the preceding Claims, wherein said fluid supply (208) comprises:
a fluid reservoir (214) sized to store an amount (216) of cooling fluid therein; and

a pump (218) configured to discharge cooling fluid from said fluid reservoir (214) towards said first manifold (210).
A power electronics assembly (200) comprising:
an array (202) of line-replaceable units (204); and

a cooling system (206) in accordance with any one of the preceding claims.
The assembly (200) in accordance with Claim 6 further comprising a self-sealing connector (246) coupled between said first manifold (210) and the line-replaceable units (204) in the array (202) such that each line-replaceable unit (204) is selectively uncouplable from said first manifold (210).
A method of manufacturing a cooling system (206) for use in a vehicle with a power electronics assembly (200) comprising an array (202) of line-replaceable units (204), said method comprising:
coupling a first manifold (210) in flow communication with the array (202) of line-replaceable units (204); and

coupling a fluid supply (208) in flow communication with the first manifold (210), the fluid supply configured to channel cooling fluid towards the first manifold (210) such that the cooling fluid is discharged towards the line-replaceable units (204) in the array (202) substantially simultaneously;

the method characterized by further comprising:
coupling a second manifold (212) in flow communication with the array (202) of line-replaceable units (204), wherein the second manifold (212) is configured to collect the cooling fluid (208) discharged towards the line-replaceable units (204) in the array (202), the collected cooling fluid comprising a flow of vaporized cooling liquid and a flow of residual cooling fluid remaining in liquid form;

coupling the second manifold (212) in flow communication with the fluid supply (208) such that a flow of residual cooling fluid is recycled towards the fluid supply (208);

coupling a condenser (220) in flow communication with the second manifold (212) via a return line (222) which is configured to receive the flow of vaporized cooling fluid and channel it towards the condenser (220), wherein the condenser (220) receives a flow of vaporized cooling fluid from the second manifold (212) through said return line (222), and is configured to condense the vaporized cooling fluid and form condensed cooling fluid; and

coupling the condenser (220) in flow communication with the fluid supply (208), wherein the condenser (220) channels the condensed cooling fluid towards the fluid supply (208).
The method in accordance with Claim 8 further comprising defining a plurality of flow control orifices (244) in the first manifold (210), wherein at least one of the plurality of flow control orifices (244) substantially aligns with each line-replaceable unit (204) in the array (202).